Generally, a solar panel is made by building up a plurality of films such as a clear electrode film, a semiconductor film, and a metal electrode film on a base material.
FIG. 3 shows a production method for a conventional solar panel. A solar panel 10 is made by adhering a solar panel module 27, which is made by building up a solar cell layer 25 on a thin glass substrate (glass substrate 26), to a covering glass which is made of a glass substrate by using an adhering sheet 14.
A covering sheet (back up sheet for rear face) 21 is adhered to the rear face, to which the solar cell layer 25 is arranged, of the solar panel 10 so as to cover the solar panel module 27 by an adhering sheet (adhering sheet having an adhering face in a rear face) 20. The periphery of the covering sheet is covered by a sealing material 22 so as to seal the solar cell layer 25.
FIG. 4 shows another production method of a conventional solar panel. In this method, a solar cell layer 25 is directly built on an entire surface of a glass substrate 15 for covering the solar cell layer 25, and is adhered to the covering sheet 21 by the adhering sheet 20. It is possible to obtain a solar panel having a desired dimension by cutting the solar panel thus constructed. The above production process has an advantage in flexibility of design.
However, a periphery of the covering glass 15 and an edge of the solar panel 25 are aligned approximately on the same line, and according to this alignment, productivity and quality of the solar panel will be degraded. That is, as shown in FIG. 5, it is necessary to arrange the sealing material 22 between a bottom face and an upper face of the solar panel so as to cover the edge of the solar panel and also to closely contact the covering glass 15 with the sealing material 22. According to the above necessities, the production process for the solar panel becomes too complex. Because the sealing material 22 is arranged to cover a part of the face of the covering glass 15, qualities such as appearance and amount of accepting light tend to be degraded. Because the sealing material 22 is arranged above the face of the covering glass 15 and a projecting portion 22c is formed by the covering glass 15, dust and contaminants tend to adhere and deposit on the covering glass 15.